Units Free vs Unit Converter For Engineers
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Units Free
Easily convert between various units across multiple categories like length, temperature, and weight. Access past conversions through a history list and send calculations via email. This free version offers core functionality with an option to upgrade for full category access.
- Multiple unit categories (length, temp, weight, etc.)
- Metric and imperial system support
- Conversion history list
- Send calculations via email
- iPad multitasking support
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Convert between many units from several categories and different unit systems (metric, imperial, ...). Features: - categories: length, temperature, capacity, weight, energy, power, pressure, area - access previous conversions from the history list - categories have different colors (in the history as well) - flip units - send calculations by email - support for the iPhone 6 and 6+ - support for the iPad multitasking (split view..) (Free version: requires upgrade to arbitrarily switch categories)
Unit Converter For Engineers
This app provides a comprehensive unit conversion tool specifically designed for engineers, offering specialized units not found in standard converters. It features offline functionality, fast search, and a clean interface, replacing the need for multiple reference materials.
- Specialized engineering units
- Offline functionality
- Fast search and instant conversion
- Fraction input mode
- Ad-free interface
- Scientific notation support
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Built for engineers who work with units most converters don’t have. No ads. No popups. No distractions. If you’ve ever opened PDFs, charts, or old handbooks to convert Rockwell hardness, wire gauge, HVAC airflow, radiation dose, water hardness, or torque units — this app replaces all of that. Units you usually can’t find in converter apps Material Hardness Rockwell (HRC, HRB, HRA), Vickers, Brinell, Knoop, Mohs, Shore Wire Gauge AWG, SWG, MCM, kcmil, diameter, cross-sectional area HVAC & Airflow CFM, ACH, BTU/h, tons of cooling, kW, airflow per area and per person Water Quality & Chemistry ppm, mg/L as CaCO₃, grains per gallon (US/UK), °dH, °fH, dKH, mmol/L, meq/L Radiation & Radioactivity Becquerel, Curie, Gray, rad Mechanical & Structural Torque, stress, density, pressure, moment of inertia (kg·m² ↔ slug·ft²) Built for real work environments • Works 100% offline in labs, plants, and job sites • Fast search and instant conversion • Scientific notation for precision work • Fraction input mode for field and construction use • Clean, engineer-friendly interface — no ads, ever This app replaces reference charts, calculators, handbooks, and repeated Google searches with one reliable tool in your pocket. Pricing 7-Day Free Trial $9.99/year full access $29.99 lifetime access Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://unitconvertx.github.io/docs/privacy.html
Screenshots
Verdict
The clearest difference is review sentiment: Unit Converter For Engineers at 100% against Units Free's 0%. Unit Converter For Engineers also leads on rating (5.0 vs 1.0) and update cadence (every 9 days vs every 5 months). Units Free's advantage is iOS requirement (5.1.1 vs 16.2). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Units Free sells 1 one-off in-app purchase and Unit Converter For Engineers sells 2 in-app purchases, starting at $9.99 per year. Whichever you choose, the download price is not the number that matters.
Unit Converter For Engineers holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews point the same way: 0% of Units Free's written reviews are positive against 100% of Unit Converter For Engineers's.
Units Free ships an update every 5 months, Unit Converter For Engineers every 9 days. The most recent releases landed on November 6, 2026 and October 30, 2026 respectively.
| Parameter | Units Free | Unit Converter For Engineers |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) | 5.0 (3 ratings) — better |
| Positive reviews | 0.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 1 | 3 — better |
| Update frequency | Every 5 months | Every 9 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Freemium |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 5.1.1 — better | 16.2 |
| Further details — not scored | ||
| Size | 3 MB | 5 MB |
| Age rating | 4+ | 17+ |
| Developer | Piet Jonas | Amanuel Abebaw |
Customer experience
Units Free
Unit Converter For Engineers
In-app purchases
Units Free
- Units Free Upgrade$0.99
Unit Converter For Engineers
- Annual Subscription7 Days trial$9.991 Year
- Lifetime Access$29.99
Questions
Is Units Free free?
Is Unit Converter For Engineers free?
Which has better reviews, Units Free or Unit Converter For Engineers?
Do Units Free or Unit Converter For Engineers have ads?
Which is updated more often, Units Free or Unit Converter For Engineers?
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